TeamEmbo

We just come back from the Cch Home Expo and were impressed with the heat that the pellet fires on display kicked out. But they need electric to run and when we worked it out our more expensive than using our woodburner. However, noting that they actually had a fan to blow the heat out OH tried an experiment with our woodburner when we got home and put a home/office desk fan just above but behind the wood burner.

We light a fire as normal and switched on the fan, it heated the room in a fraction of the time, instead of the heat going straight up from the wood burner it pushed it out like the heat pump and in 1 hour the room temp went from 14 to 21 degrees and the humidity dropped by 5%

what a clever man i've married

Frenchy

We use a celling fan in our lounge for the same effect, it has a winter and summer mode

We are however about to install a heat transfer kit to get some warmth into our daughters room. We are going to the expo here in Blenheim next week

TeamEmbo

Yep, we also have a ceiling fan BUT putting the desk fan directly behind the woodburner just above the top of it pushed more heat round the room quicker and more effectively!

UKNZAUS

WOW I never thought of that! Thanks for the tip

hazeandsteve

Isn't it slightly risky?
Just thinking about the NZ Fire brigade's ad advising moving everything at least 1m from the burner.

TeamEmbo

thought of that, but the fan is actually pushing the heat away from it's self so it doesn't get hot.

the rule is, if the fire is lite the fan has to be on

lardyl

erm - radiant heat - erm

depending upon how close the heat source is to the fan then you could have a problem with melting plastics from radiant heat transfer (you know like glowing coals) as opposed to convective heat (warm air rising, etc - that you rightly say will be dealt with by the fan blowing accross the flue). But if the fan is working then the cool air it is drawing would probably overcome any radiant "gain" (analogous to the solar "gain" you get in your Kiwi greenhouse/home when the sun comes out!!)

one problem that could occur - off the top of my head - is that cooling the flue (which is what you are doing by blowing cooler air past it) could reduce the efficiency of the flue (as a chimney) in the early stages after it is lit and you might get more "soot" build-up in the flueway as well as taking longer for the burner to "settle" once its on. Perhaps you could leave the fan off for a bit to start with?

You might need to balance that with the convective heat transfer to the fan. My concern is that heating up an electrical appliance that is not designed to operate at elevated temperatures is a "no no" on the safety front - only you can judge how hot the fan is getting and compare that to the instructions the manufacturer supplied.......

and my experience is that some of these desk/pedastal fans don't need too much encouragement to catch fire themselves .....

/wonders: where's the crossed-fingers smiley that I asked the mods for years ago????/

lapsed kiwi

On a vaguely related topic - here's a hot tip for those with heat pumps. Clean the air filters! I hadn't cleaned ours since they were installed two years ago and one was getting a bit pathetic in terms of heat output. The filters were very easy to remove from the unit, and had a layer of dust which was blocking the air inlet flow. Thirty seconds with a soft brush on the vacuum cleaner, and the heat pump is back to its former self. You know how it is when something gets slowly worse - I am now amazed how much heat the thing is chucking out

TeamEmbo

Yep we have thought of these things. We switch the fan once the fire has taken and is producing heat. It is only on a low setting just to push the rising hot air out into the room so it isn't actually cooling the flue. The way our woodburner is situated at an angle on a raised stone hearth with stonework behind means there is sufficient space behind the woodburner to have the fan set back about 2 foot from the flue. The fan and its plastic base (where the switches are) don't get hot as they aren't close enough to the back/top of the woodburner which gets incredibly hot or the flue. And, of course, the cable is tucked well away from the woodburner as well.
We regularly use the chimney cleaner granules to help alleviate flue build-up. And we try and remember to vacuum off the filters on the heat pumps too, although usually only remember when we notice they're not working as well as they should!

lardyl

Just trying to keep you safe

lardyl

One trick that worked for me using a pedestal fan was when we had a nasty persistent smell in the house...... nope, not me or my bull$h!t.......

Get some of that great nulodour (or whatever its called) liquid (comes in a little green bottle like aromatherapy oil) and sprinkle it onto some sheets of newspaper that were torn and inserted through the impeller side of the fan grille then run the fan (so they look like the old fashioned "fan is running" ribbons)......result the nasty smell in the air was replaced by the erm, not quite so unpleasant, smell of the oil..............

TeamEmbo

Ah thank you! Now ... after saying how easily the things self combust I can't believe you actually put oil and newspaper anywhere near the thing!!!!!

Good tip though. Perhaps I could combine that tip with my current set up to get rid of doggy odours, see if I can't really turn it into a towering inferno!!!!

lardyl

Nah the fans usually fail because of cheap cr@p chinese motors burning out and poor connectors and cracked supply cords and........

The oil shouldn't make much difference to the thing igniting - would cause a problem if it did though as the fuel load would be much higher - only problem I can forsee is if the paper gets into the drive shaft and stops the fan and stalls the motor - but our fan was a good quality one which should have thermal protection in the motor to prevent that causing a fire......... :cross fingers smilie:

My hot tip is don't scrimp on the cost of portable appliances, especially el-cheepo fan heaters - I have been to a fire involving a real shocker of one in NZ already (last heating season that was) and it was only a month or so old at the time

lardyl

doubt you'll get a flamethrower from the fan but I'd avoid atomising petrol or aerosol propellant/air freshener behing the flue or behind the electric fan as you might get a "kboom-kboom-shake-the-room" effect instead !